Goals: Finish the hanging system
Things we did/Why we did it:
Problems: The elastic assist was too strong, when unneeded, but too weak when needed
Results: Objective failed, decided to give up hanging
Misc. Notes: N/A
Future Plans: Perfect the funnels
Today, we made a last ditch attempt at constructing the hanging system
We first had two main goals. The first was creating a better hanging mount, and the second was removing what we had currently. While we were removing the old system (cutting string, unscrewing 4 screws), the other group gathered an aluminum channel and cut rail ends. Using these pieces, we created a U shaped bar which should have bypassed the cortex. Once the hanging system was removed, we took the sprocket and linear slide components and attached it to the U shaped bar, then mounted it to the intake similar to before. The group that was detaching the mount now focused on adding additional rubber bands throughout the robot
Before, when the robot rose to full height, the linkage support could not keep the intake up when the string became taught. Because of this, slack was created, and the intake system would not deploy. So, we reasoned that by adding rubber bands to the intake and deployment, we could maintain lift height and keep a consistent expansion.
We first added rubberbands to the deployment itself. We attached rubberbands from the furthest standoff, looped it by the sprocket, and attached it onto the linear lift. We experimented with the hole placement and rubberband amount for about 20 minutes, and determined that we should use about 4 rubberbands, 13 holes away. With this arrangement, the system would fling up with the slightest agitation, so we reasoned that force decay should occur quick enough by worlds. While this occurred, we realized that one side had rubber bands strung around the bare standoff, and the other side had rubber bands through the standoff. Because the side with rubber bands around the standoff was slightly too strong, we copied the other side.
We tested the system again, and we still saw that the intake was bending backwards. The linkage support on the intake was not doing it’s job. So we added more rubber bands and slowly tightened the zip tie until it maintained height. However, by the time the linkage would support the intake, it supported it too well. The hanging system would deploy easily when the lift is up, but when the lift is dropping, the lift would bend forward. This became so bad that the chain on the chain bar actually snapped one time.
With time quickly running out, and knowledge of worlds coming soon, we decided to give up on hanging and stick to the original goal of dominating autonomous and equalizing in driver control. We removed the hanging system, but kept it assembled if all goes well.
Photos: 1. Driver practice 2. Amanda Overseeing the Hanging system 3. Close up of U shaped bar 4. Elastic Assist on Intake linkage 5. Right Side Funnels In dimension 6. Rubber banding
Goals: Perfect the funnels, Stabilize the intake, Driver Analysis
Things we did/Why we did it: Replace the right side funnel mount. Apply proper spacers, replace axles, Analyzed various scenarios in driver control,
Problems: The right funnel does not retract all the way due to chain tension.
Results: The funnels had a more professional feel, and became faster. However, the right funnel has problems fully retracting
Future Plans: Hold officer elections, hold officer training, Continue Driver Practice, Create Autonomous Code
Today, we focused on maximizing the funnels performance. The funnels were opening and closing at acceptable rates, however the funnels cannot retract completely, so we focused on numerous small details in hopes to boost the funnels performance.
The first thing we did was change how the funnels were mounted. Rather than using a full 8” rail, we found cut rails from previous years and swapped out the rails. This resulted in a lighter, more compact profile. Since we lose points of connection, we then placed a total of 4 standoffs to connect the funnels to the drivetrain, increasing stability.
Next, we then inspected the bearings. We noticed that some axles were bent, sprockets were missing spacers, and holes were missing pillow blocks. We removed axles from the bearings of interest and applied pillowblocks for a rounded mount, and replaced the bent axles with straight ones. As we applied the straight axles, we inspected the position of the gears and carefully added spacers to keep the system in place. Then, we sealed the system off with collars. While this was going on, we also applied 1 by 25 from the chain bar mount of the funnels, onto the initial joint of the arm. This eliminated cantilevering.
After these changes, we tested the funnels. The left side of the funnels retract very well, however the right side of the funnels do not. After closer inspection, we noticed 5 things. One, the right side of the drivetrain is missing a standoff, causing the funnels to wobble greatly. Two, the chain had a lot of slack. Three, the motor mount for the funnels is bending greatly due to the cantilevered mount. Four, the right side of the drivetrain had a loose locknut. And 5, the inner right side rail was completely missing screws.
Because of this, we took away a chain link, looked for a standoff, added a second support to the cantilevered mount, tightened the locknut, and replaced the screws. We could not find a standoff, but the other four changes did not allow the funnels to retract completely. If we find a standoff, and replace chain with a ziptie, the funnels should retract completely
In addition to this, we studied up on scenarios which occurred at U.S. Open. Using the competition videos we found, we developed possible driver control strategies to counter the defensive techniques we've seen, as well as catalyze our own strategy. To do this, we've created a series of steps which we need to execute, as well as a procedure for our ally.
To close this up, we also attempted a custom power curve for our driver. Unfortunately, it was not successful. After talking with our programmers, we believe that they may have used the wrong channels.
Photos: 1. Top View of the Bot, 2. new brace for the funnels, 3. View of the funnels expanded 4. New Spacers on the Left funnel 5. Loose locknut on the right side of the drive train 6. missing screws on the right side of the drive train 7. Missing standoff on the right side of the drive train 7. Severely Bent axle on the left funnel 8. New Funnel Joint 9. Top view of right funnel stored 10. Close up of the intake's linkage support mounting holes 11. Another view of linkage support mounting 12. Another view of linkage support mounting 13. Linkage Support all the way down 14. zoomed out view of linkage support 15. Rats nest, what we have to deal with if we decide to move the motor 16. Close up of the rats nest
Buggy Power Curve
Custom Formula, Courtesy of Mu Alpha Theta
Goals: Presidential Elections
Things we did/Why we did it: Presidential Rap/Tradition, Presidential Debate/info, Cast Ballots, Tally Votes
Results: To be determined
Misc. Notes: We got emails from Middleton and Tampa Prep High School saying that we can visit them and use their field
Future Plans: create advertisements, develop worlds autonomous, practice driving, practice for interviews, refine/maintain robot, repair the intake
Today, we had Presidential and Vice Presidential elections.
This year, 4 members ran for positions: Eric Barker, Ivy Bennett-Ford, Louis Leon, and Amanda Organ. They continued the tradition of rapping, and gave a whopping 6 minute bout. Unfortunately, because the rap contains a lot of inside jokes and sniping comments, we will not make the recording public. However, before this rap was created, the 4 agreed that this rap doesn't reflect the member, nullifying future resentment.
Due to the number of members that were absent this meeting due to other competitions, absentee ballots will be submitted at the start of Monday's meeting. With this, the co-presidents, and vice president elects will be determined
How many people can work on a robot at the same time?
3/12/14: Bonus Meeting
Goals: Nothing in specific. Just work towards the strategy
Things we did/Why we did it: Modified the tower rollers in hopes to grab the large balls at full speed; Tried drilling into sprockets to make a chain bar on the funnels system. Uploaded the standard middle zone autonomous with encoder values and tuned it for better reliability and consistency. Apply preset encoder heights. Applied an elastic backing for the 3rd bucky ball
Problems: Sometimes the robot would get stuck into an infinite loop of the code. Conflictions occur with the funnels. The preset lift heights for pushing the large balls were too low.
Results: The 18 point autonomous has consistent paths, increasing reliability and aims for the large balls to speed up human interaction. The robot can grab large balls without driving slowly. The robot now has preset lifting heights. The large ball storage is sturdier
Misc. Notes: Changing logic from “else”s to “if else”s can cause the code to get stuck in a loop. We realized that the 3rd bucky ball can pose problems in the new autonomous
Future Plans: We need to finish up work with the funnels: make sure they fit in dimension, deploy appropriately, and grab floor buckies. In addition to this, we need to develop the new autonomous, further tune the bucky ball intake, practice driving, and retension the lift, and reinforce the the lift.
Today was a preparatory meeting for FRC. However, we were able to squeeze some vex time. Because of this, our goals were quite scattered. However, we were motivated with our work, and got a lot of things done.
First off, our programmer returned the robot to the shop. During break, he rewrote the middlezone autonomous we used in states with encoder values. Thanks to this, the autonomous is much more consistent in its paths. Before he could start coding, he had to finish up mechanical changes. He reattached the drive train motors, rewired the robot, and mounted encoders onto the lift and funnels system. We decided to go with encoders simply because we do not have potentiometers. In addition to this, he attached a bracing below the drivetrain to increase stability.
Slideshow features: 1. First Attempt at a chain bar without modifying parts 2. Inserting encoders on the funnels 3. Encoder on the lift 4. Encoder on the drivetrain, 5. Bottom view of the drivetrain (ignore offset) 6. Doubled up tire-less wheels
At the start of the meeting, we developed a new set of rollers to grab the large balls. We realized that the tank tread on UVM’s rollers allowed the intake to dig into the large ball. So, we decided to mimic this effect with additional rubber bands. Instead of 4 rubber bands padded out like last time, we added 8 rubber bands which crossed over each other, creating a large bulge about a quarter inch deep. We only replaced 1 side of the intake and we could immediately grab without a wall at full speed. We replaced the other side just for consistency. We then filmed the robot while grabbing. Looking at the footage, we noticed that the robot grabs the large balls well, with very little wheel slip. Because of this, we believe we aren’t grabbing as quickly as UVM because our intake isn’t geared for speed.
Above: Adding the first of the rubber bands in a crossing manner
After this, we then worked on the funnels system. We wanted to turn the arm system into a chain bar system so we could encompass all 3 Bucky balls on the bump at the same time. By doing this, we believe we’ll consistently grab 3 Bucky balls in autonomous. To solve our past problem with the offset chainbar, we decided to drill though regular tension sprockets. We loosely screwed the sprockets into damaged 60 tooth high tension gears. The screws kept the sprocket fairly flat, but it also allowed the sprocket to adapt to the drill bit. We then used a drill press and made clean holes through the sprockets. Though it wasn’t perfectly centered, we got the effect we wanted after mounting them. We could have improved this method by using a balance to make sure the sprocket was drilled straight. The result can be seen below
After this our programmer took the robot to adjust the code. We had numerous disconnection issues, so we hope the vexnet 2.0s coming in will solve our problems. When it did run, distances were astonishingly consistent. As for mistakes, we realized that the funnels did not close enough. Because of this, the funnels would run into the wall. To fix this, we decided to retract the funnels slightly. Using the extra time, the programmer decided to add a sweeping action. Rather than manually turning the robot, the robot would turn, facing the large ball. This would shave the time needed for repositioning. All that the human player would do is realign slightly and trigger the limit switch to push the large ball. When we got to the large ball sequences, we noticed that the lift was very low, which increased the chances of running into the barrier. So he then raised the encoder values slightly to increase the arm height, adding more tolerance.
As the end of the meeting approached, we made very minute changes. For one, we doubled up the zipties on our large ball storage. We manually put a large ball and found out it supported the large ball with moderately violent pushing. However, when we grabbed a large ball, and did a test where we spun the drivetrain around violently, the ball came off. We realized that elongating our storage system led to moving back the ziptie supports. Because of this, the zipties do not fully cover the first large ball, making it susceptible to falling out.
Foraging ahead, we need to trickle in some driver practice to steadily build muscle memory of our driver. In specific, we need to focus more on large ball skills because that area will change the tides in our strategy. In addition to driver practice, we need to finish up the last of the funnels and lift system.
Goals: Figure out the price for worlds; Figure out how to develop the robot for worlds
Things we did + why we did it: We looked at prices for registration, plane tickets, food, car rentals, housing, shipping the robot, and disney. By looking at the prices, we can estimate how much money we need to raise. We then discussed strategic goals for worlds
Miscellaneous Note: Worked In parallel to speed up research
Results: We finished researching early. We found out that it would cost the team around $10,320 to attend without funding, or about 1,032 per person
Future Plans: Finalize plans to the robot and start applying them
At the very start of meeting today, we grouped together and agreed to work on funding and future plans. We knew that worlds was going to be intense, and without a well thought out plan, we would make numerous blunders.
Throughout the meeting, we researched prices to estimate cost for the trip to worlds. We documented our findings here:
We browsed through numerous websites to find the lowest rates for plane tickets housing. We found tickets as low as $500 round trip, and realized that renting a house was cheaper than staying at a hotel. Because of this, we saved over $600 per person. After much discussion, we also agreed that we should visit disneyland. Because it’s within the vicinity, we realized that if we flew and arrived tuesday morning, we could spend the day having fun.
After research was finished, the team discussed what goals we should aim for in Worlds. We all pretty much agreed that we shouldn’t aim for the Excellence, Skills, and amaze awards because we lack the pneumatics to keep up with shooting and hanging robots. However, we all agreed that we have a great chance of winning the design award because of our notebook. If we focus solely on this award, we can ensure that we win a prestigious award at competition
As for the robot, we discussed various strategies
1. De-scoring: Play the game as normal, rush to the goals at the end, and de-scoring and re-scoring
2. Double Hanging: Play the game as normal, hang with an ally while de-scoring opposing game pieces
3. Autonomous Domination: Play the game as normal, Equalize all other areas
4. Shooting: Play the game as normal, shoot game pieces into the goal zone
5. Mixing and matching the strategies: Combine the strategies for more effect
of the 5 strategies, we currently believe strategy 3 is most appropriate for us. We know we will not get the funding necessary to purchase pneumatics and electronics to compete with other robots around the world, as well as eliminate the kinks other teams have, however, if we continue to exploit our best trait, we can create an irreversable edge. If we do decide to go with strategy number 3, the most critical changes would be improving the funnels, and adding sensors. Improving the large ball intake, bucky ball intake, and turning would be extra. In order to improve the funnels, we would need extra room to enlarge the system. Luckily, by swapping mecanum wheels with omni wheels, we can improve our turning and create room for the funnels at the same time.
Goals: Establish a price for Anaheim; Swap the drivetrain with tank
Things we did/Why we did it: Researched additional costs / Used to lower spending; Removed the mecanum wheels with tireless 4” wheels in the back, and omni wheels in the front / Improves turning and traction. Tested grabbing ability with extra time
Problems: A bit difficult replacing chain, turning was a bit difficult cause the lift started to drag
Results: We lowered the cost of the trip by $200; The drivetrain gained better turning; realized that the lower limiters need to be replaced, and the rollers need to be lowered
Misc. Notes: We tried doubling up the rear wheels. As a result, turning wasn’t noticeably affected, but traction seemed to vary based on how long the drivetrain was stationary. This may be because the drivetrain sinks into the tiles over time
Future Plans: Work on fundraising the money for worlds, experiment with wheels sinking into foam, directly mount motors to the drivetrain, mount encoders into the robot for future programming, turn the funnels into a chain bar, develop a crate to ship the robot, apply lower limiters and decrease the height of the intake
Today, we split into two groups. One group was focusing on fundraising, and the other focused on improving the robot.
For the fundraising group, we noticed that the house we wanted to rent was taken. So, we looked for another house. In the end, we found a house for about $2200. Though this was more expensive than the other house, with the increase of the expected number of people attending, and a greater fundraising effort, we could afford something with more class. Furthermore, after more research, we found $350 plane tickets. This was $150 than the other plane tickets we found. With further investigation in these two areas, we saved the team an additional $200.
For the engineering group, the first thing we wanted to target was improving the drivetrain. By speeding up the drivetrain and indirectly mounting the motors, the drivetrain did not have the torque to strafe with mecanums. So, looking at our strategy, we realized that speed and traction was more critical than mobility. Because of this, we wanted to replace our mecanum wheels with omni wheels and regular wheels. The front wheels will be replaced with omni wheels, which gives us excellent turning, while the back wheels will give us excellent sideways traction. Because the goal will be cupped by the front of the drivetrain, we reasoned that traction in the front isn’t necessary. With prior research, we found out that tireless 4 inch wheels have one of the highest tractions in all directions. So we decided to use these wheels in the back.
Now with a plan, we removed the mecanum wheels and installed the omni wheels up front, and traction wheels in the back. The transition wasn’t too difficult – the hardest part was rechaining the wheels. With little thought, the experience members got it on in 10 minutes. The freshmen took about 40 due to their inexperience. Nevertheless, only half of the meeting was spent on changing the drivetrain. Afterwards, we tested the robot. Immediately, we noticed that our turning was a bit the same. It was slightly faster, but it also didn’t revolve around the center of the robot. Because of this, we quickly changed the code from mecanum to tank drive. After this change, turning was much faster. Rather than the previous 3 seconds for a 180 degree turn, we spent only 1.6 seconds. After driving around, we started to test grabbing. Immediately, we noticed that our large ball intake and bucky ball intake was much better! We could easily grab the third bucky and we grabbed a large ball in about a second. However, we tried turning around again and realized that our turning slowed drastically. We did a 360 degree turn and noticed a mark around the robot. We realized something was dragging. We followed the line and realized that the chain bar was dragging again. We then remembered that we took off the standoffs during programming skills due to an entanglement problem. We then raised the intake to its previous height and noticed that our grabbing was slower. So because of this, we realized that we need to lower the height of the rollers, and reinsert the lower limiters. We did more rolling tests and realized that our back left wheel is still coming off the ground. Because of this, our turning is not optimal.
After this, we played with the idea of doubling up our back wheels. We saw this idea from Middleton robotics, a local school which won the world championships 2 years ago, and became the world finalist last year. In their drivetrain, they doubled up all wheels to increase traction. We then tested this concept ourselves. At first, we were confused. We had variable pushing resistance. Sometimes it was really easy to push, other times, it was almost impossible even with human power. We then realized that when it was very easy to push, the wheels didn’t leave deep markings. When it was difficult, it was the opposite. Because of this, we realized that the wheels sinking into the foam tiles played a huge part. We noticed that our turning was slightly improved because the wheels always made contact, but the robot’s turning still isn’t centered. To test sinking, we’ll get a separate axle with wheels, and we’ll find an optimal distance where foam wraps around the wheels twice. If this distance is reasonable, then we may keep the doubled wheels.
Many people began to question the legality of removing the tires off 4 inch wheels due to field damage. We plan on creating a Q/A on the vexforum, but through our tests, the wheels do not dig into the foam tiles enough to damage. In addition to this, we want to continue focusing on improving the drivetrain, but we can also work on improving the intake in parallel. We also need to establish whether we are meeting over spring break or not.
Goals: Mount encoders for the drivetrain and directly mount motors to wheels
Things we did/Why we did it: We removed the drivetrain motors and front wheels to directly mount motors and provide space for the wheels. We worked on adding encoders to the funnels and lift system. We worked on adding a chain bar to the right side of the funnels system to make it easier to grab bucky balls. We also decided to weigh the robot and test how much force it can resist.
Problems: We found it difficult to create a chain bar due to it’s thickness, and because the sprockets need round holes. We also found it difficult to mount encoders onto the lift system and the funnels system
Results: We found out our robot weighs about 16 pounds, the robot can resist about 6 to 8 pounds of pushing force, and that our engineering notebook weighs 12 pounds. We mounted encoders on the lift system and drivetrain, but didn’t figure out how to mount encoders onto the funnels. We did not get to remount the drivetrain motors
Misc. Notes: The robot went home with our programmer over break so he could tune encoder values as needed.
Future Plans: We need to finish up work with the drivetrain and encoders. While this is going on, we need to get our driver used to tank drive code. Most of this should be finished over the break. To get our driver used to tank drive, we can set up an obstacle course and borrow one of our sister FTC team’s robots.
Today, we followed a very relaxed pace. Though we wanted to finish up the drivetrain so our programmer could program the robot over break, we only mounted the encoders and remounted the wheels. We didn’t get to reinstall the motors like we wanted.
In addition to this, we worked on adding encoders to the lift system. We realized that we didn’t have space for encoders in the gear tower itself, so we decided to mount the encoder on a tensioner, which also rotates with the lift. Though this orientation would require extra wiring for the robot, we hope that the bonus of determining lift height will far outweigh the engineering difficulty. We also had problems mounting encoders onto the funnel system, however we hope we can finalize this after we finalize the drivetrain.
The last aspect we worked on today was the funnels system. We tried turning the right side of the funnels into a chain bar, but we ran into packaging issues. First of all, the funnels operate through chain. Because of this, the axles within the funnels turn with the system. If we were to mount a sprocket stationary, like the chain bar on our lift, the system would turn into an arm. Unlike the sprocket, sprocket combo with the funnels chain bar, the gear sprocket combo has a circular insert and a square insert. We did not want to drill circular holes into the sprockets.